Traditionally, digital watermarking is used to enforce intellectual property rights and protect digital media from tampering. With the fast growth of various TV check-in applications, it has also been utilized to provide a mechanism to let second screen devices, such as mobile phones and Tablets, to automatically discover which channel and program is showing on the main screen device, e.g. a TV set.
For instance, there are applications that enhance the experience of watching certain TV programs by providing synchronized interactive content and social media functionality on the tablets such as an iPad. This is achieved by relying on audio watermarks that are inserted into nearly every TV program at the service provider site in the US to support Nielsen's industry standard TV audience ratings service. The watermarks, inaudible to the human ear, can be detected and decoded through the microphone of mobile devices in a normal living room setting. As soon as the audio watermark for the TV program is detected by the iPad, the corresponding application will retrieve sync-to-broadcast content from the broadcaster and show it on the tablets.
The problem with existing watermarking solutions of inserting audio watermarks at the head-end is that it is impossible to determine user interface (UI) interaction data that rely on each user's behavior, such as which programs the user has watched recently, since these data can only be learned at local devices such as the set-top-box (STB). As a result, watermark payloads in existing solutions only contain codes that identify the content's source distributor/network as well as a date/time stamp. In addition, inserting the watermarks will cause delay in the transmission of the digital data stream of the TV program because it requires re-encoding the audio data stream before transmission. This will lead to negative user experience, especially for live TV programs such as live broadcast of football games. Moreover, this kind of solution has low flexibility in that it can only be implemented by, or under close cooperation with, service providers.
The present invention solves the problem of existing solutions and proposes a content program discovery by generating and embedding watermark information in local devices.